import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';

type PointerListener = (event: PointerEvent) => void;

const makePointerEvent = (
  type: string,
  event: Partial<PointerEvent> = {}
): PointerEvent =>
  ({
    buttons: 1,
    clientX: 10,
    clientY: 20,
    isTrusted: true,
    pointerId: 1,
    pointerType: 'mouse',
    pressure: 0.5,
    timeStamp: 100,
    type,
    ...event,
  }) as PointerEvent;

const toPoint = (point: ArrayLike<number>): Array<number> => Array.from(point);

class FakeCanvas {
  public readonly capturedPointerIds: Array<number> = [];
  public readonly releasedPointerIds: Array<number> = [];
  public width = 300;
  public height = 200;

  private readonly listeners = new Map<string, Set<PointerListener>>();

  public addEventListener(
    type: string,
    listener: EventListenerOrEventListenerObject
  ): void {
    const listeners = this.listeners.get(type) ?? new Set<PointerListener>();
    const pointerListener =
      typeof listener === 'function'
        ? listener
        : (event: Event) => listener.handleEvent(event);
    listeners.add(pointerListener as PointerListener);
    this.listeners.set(type, listeners);
  }

  public removeEventListener(
    type: string,
    listener: EventListenerOrEventListenerObject
  ): void {
    const listeners = this.listeners.get(type);
    if (!listeners) {
      return;
    }

    listeners.delete(listener as PointerListener);
  }

  public dispatchPointerEvent(type: string, event: Partial<PointerEvent> = {}): void {
    const pointerEvent = makePointerEvent(type, event);

    this.listeners.get(type)?.forEach((listener) => listener(pointerEvent));
  }

  public getBoundingClientRect(): DOMRect {
    return {
      bottom: this.height,
      height: this.height,
      left: 0,
      right: this.width,
      toJSON: () => ({}),
      top: 0,
      width: this.width,
      x: 0,
      y: 0,
    } as DOMRect;
  }

  public setPointerCapture(pointerId: number): void {
    this.capturedPointerIds.push(pointerId);
  }

  public releasePointerCapture(pointerId: number): void {
    this.releasedPointerIds.push(pointerId);
  }
}

const makeSwipePipeline = () => ({
  addSwipeSegment: vi.fn(),
  clearSwipes: vi.fn(),
});

const createPointerInput = async () => {
  const { GardenPointerInput } = await import('./pointer-input');
  const { settings: runtimeSettings } = await import('../settings');
  const canvas = new FakeCanvas();
  const audio = {
    beginGesture: vi.fn(),
    endGesture: vi.fn(),
    start: vi.fn(),
    stroke: vi.fn(),
  };
  const brushPipeline = makeSwipePipeline();
  const eraserAgentPipeline = makeSwipePipeline();
  const eraserTexturePipeline = makeSwipePipeline();
  const eraserPreview = {
    isPointerInsideCanvas: vi.fn(() => true),
    setEraseMode: vi.fn(),
    setPointerHoveringCanvas: vi.fn(),
    update: vi.fn(),
  };
  const onStartDrawing = vi.fn();
  const onEraseGestureEnded = vi.fn();
  const spawnStrokeAgents = vi.fn();
  const input = new GardenPointerInput({
    audio,
    brushPipeline,
    canvas: canvas as unknown as HTMLCanvasElement,
    eraserAgentPipeline,
    eraserPreview,
    eraserTexturePipeline,
    getDevicePixelRatio: () => 1,
    getMirrorSegmentCount: () => 1,
    onEraseGestureEnded,
    onStartDrawing,
    spawnStrokeAgents,
  } as unknown as ConstructorParameters<typeof GardenPointerInput>[0]);

  input.attach();

  return {
    audio,
    brushPipeline,
    canvas,
    input,
    onStartDrawing,
    runtimeSettings,
    spawnStrokeAgents,
  };
};

describe('GardenPointerInput drawing startup', () => {
  beforeEach(() => {
    vi.resetModules();
    vi.stubGlobal('localStorage', {
      clear: vi.fn(),
      getItem: vi.fn(() => null),
      removeItem: vi.fn(),
      setItem: vi.fn(),
    });
  });

  afterEach(() => {
    vi.unstubAllGlobals();
  });

  it('allows pointer drawing immediately', async () => {
    const { audio, brushPipeline, canvas, onStartDrawing, spawnStrokeAgents } =
      await createPointerInput();

    canvas.dispatchPointerEvent('pointerdown', { pointerId: 7 });
    canvas.dispatchPointerEvent('pointermove', {
      clientX: 60,
      clientY: 80,
      pointerId: 7,
      timeStamp: 120,
    });

    expect(onStartDrawing).toHaveBeenCalledTimes(1);
    expect(audio.start).toHaveBeenCalledWith(expect.anything(), { userGesture: true });
    expect(audio.beginGesture).toHaveBeenCalledTimes(1);
    expect(brushPipeline.addSwipeSegment).toHaveBeenCalledTimes(2);
    expect(spawnStrokeAgents).toHaveBeenCalledTimes(2);
    expect(canvas.capturedPointerIds).toEqual([7]);
  });

  it('starts drawing from a fresh pointerdown', async () => {
    const { audio, brushPipeline, canvas, onStartDrawing, spawnStrokeAgents } =
      await createPointerInput();

    canvas.dispatchPointerEvent('pointerdown', { pointerId: 9 });

    expect(onStartDrawing).toHaveBeenCalledTimes(1);
    expect(audio.start).toHaveBeenCalledWith(expect.anything(), { userGesture: true });
    expect(audio.beginGesture).toHaveBeenCalledTimes(1);
    expect(audio.stroke).not.toHaveBeenCalled();
    expect(brushPipeline.addSwipeSegment).toHaveBeenCalledTimes(1);
    expect(spawnStrokeAgents).toHaveBeenCalledTimes(1);
    expect(canvas.capturedPointerIds).toEqual([9]);
  });

  it('flushes the delayed smoothed stroke tail on pointerup', async () => {
    const { brushPipeline, canvas } = await createPointerInput();

    canvas.dispatchPointerEvent('pointerdown', { pointerId: 9 });
    canvas.dispatchPointerEvent('pointermove', {
      clientX: 60,
      clientY: 80,
      pointerId: 9,
      timeStamp: 120,
    });
    canvas.dispatchPointerEvent('pointerup', {
      clientX: 60,
      clientY: 80,
      pointerId: 9,
      timeStamp: 140,
    });

    expect(brushPipeline.addSwipeSegment).toHaveBeenCalledTimes(3);
    expect(toPoint(brushPipeline.addSwipeSegment.mock.calls[1][0])).toEqual([10, 20]);
    expect(toPoint(brushPipeline.addSwipeSegment.mock.calls[1][1])).toEqual([35, 50]);
    expect(toPoint(brushPipeline.addSwipeSegment.mock.calls[2][0])).toEqual([35, 50]);
    expect(toPoint(brushPipeline.addSwipeSegment.mock.calls[2][1])).toEqual([60, 80]);
  });

  it('uses coalesced pointer samples for smoother brush segments', async () => {
    const { audio, brushPipeline, canvas, spawnStrokeAgents } =
      await createPointerInput();

    canvas.dispatchPointerEvent('pointerdown', { pointerId: 9 });
    audio.stroke.mockClear();
    brushPipeline.addSwipeSegment.mockClear();
    spawnStrokeAgents.mockClear();

    canvas.dispatchPointerEvent('pointermove', {
      clientX: 40,
      clientY: 20,
      getCoalescedEvents: () => [
        makePointerEvent('pointermove', {
          clientX: 20,
          clientY: 20,
          pointerId: 9,
          timeStamp: 110,
        }),
        makePointerEvent('pointermove', {
          clientX: 30,
          clientY: 20,
          pointerId: 9,
          timeStamp: 115,
        }),
        makePointerEvent('pointermove', {
          clientX: 40,
          clientY: 20,
          pointerId: 9,
          timeStamp: 120,
        }),
      ],
      pointerId: 9,
      timeStamp: 120,
    });

    expect(audio.stroke).toHaveBeenCalledTimes(3);
    expect(spawnStrokeAgents).toHaveBeenCalledTimes(3);
    expect(brushPipeline.addSwipeSegment.mock.calls.length).toBeGreaterThan(3);
  });

  it('passes normalized audio geometry context with stroke events', async () => {
    const { audio, canvas } = await createPointerInput();

    canvas.dispatchPointerEvent('pointerdown', { pointerId: 9, timeStamp: 100 });
    canvas.dispatchPointerEvent('pointermove', {
      clientX: 40,
      clientY: 50,
      pointerId: 9,
      timeStamp: 150,
    });

    expect(audio.stroke).toHaveBeenCalledWith(
      expect.objectContaining({
        canvasSize: [300, 200],
        elapsedSeconds: 0.05,
        from: expect.anything(),
        isErasing: false,
        to: expect.anything(),
      })
    );
    const stroke = audio.stroke.mock.calls[0][0];
    expect(toPoint(stroke.from)).toEqual([10, 20]);
    expect(toPoint(stroke.to)).toEqual([40, 50]);
  });

  it('caps curve tessellation with the brush curve resolution setting', async () => {
    const { brushPipeline, canvas, runtimeSettings } = await createPointerInput();
    runtimeSettings.brushCurveResolution = 2;
    runtimeSettings.brushSize = 1;

    canvas.dispatchPointerEvent('pointerdown', { pointerId: 9 });
    canvas.dispatchPointerEvent('pointermove', {
      clientX: 10,
      clientY: 60,
      pointerId: 9,
      timeStamp: 120,
    });
    canvas.dispatchPointerEvent('pointermove', {
      clientX: 60,
      clientY: 60,
      pointerId: 9,
      timeStamp: 140,
    });

    expect(brushPipeline.addSwipeSegment).toHaveBeenCalledTimes(4);
  });
});